Daily challenges are one of the simplest engagement features you can add to a games site — Wordle made the pattern famous. On Classroom Games , a collection of free learning games for teachers (math, typing, spelling, reading comprehension, geography, fractions, multiplication, sight words, brain breaks and more), the homepage shows one "Today's Pick" with a points goal. It resets at midnight, and there's one pick per day. The interesting part: you can build this without a server . Here's t...